Đánh giá ảnh hưởng của các chủng nấm Isaria javanica đối với sâu xanh bướm trắng Pieris rapae L. (Linnaeus) (Lepidoptera: Pieridae) trong điều kiện phòng thí nghiệm

Abstract

The cabbage white butterfly Pieris rapae is a common pest of cruciferous vegetables. The entomopathogenic fungus Isaria javanica plays a significant role in pest control. This study evaluated the efficacy of three I. javanica isolates (B2401, B2402, B2405) to control second- and third-instar larvae of P. rapae at three experimental concentrations: 1 x 10⁶; 1 x 10⁷; 1 x 10⁸ CFU/mL under laboratory conditions (22 ± 1^oC, 72 ± 3% RH, 14L:10D). The objective was to provide fundamental data for the selection and development of effective biological control agents for this pest. The results showed that all fungal isolates were effective in causing larval mortality. Notably, the isolate I. javanica B2405 at 1x10⁷ CFU/mL demonstrated superior control of P. rapae, achieving a mortality of 80% and a mycosis incidence of 70% after 8 days of observation. The developmental cycle of I. javanica on the host P. rapae ranged from 16.31 to 18.66 days. These findings confirm the potential of I. javanica B2405 at 1x10⁷ CFU/mL as a promising biological agent for developing biopesticides against P. rapae. This research provides a new direction for practical agricultural applications, contributing to a reduction in the use of chemical pesticides in crop production.